Vibratory finishing



Nov. 13, 1962 R. w. MOORE VIBRATORY FINISHING 2 Sheets-Sheet 1 Filed Jan. 27, 1960 liIIIII'lIl INVENTOR ATTORNEYS illlllll Nov. 13, 1962 R. w. MOORE 3,06

VIBRATORY FINISHING Filed Jan. 27, 1960 2 Sheets-Sheet 2 x 'llllllllllli 1111111111 [NVENTOR ATTORNEYS United States Patent "ice 3,063,207 VIBRATURY FINISHING Ralph W. Moore, Hagerstown, Md., assignor to Pangborn Corporation, Hagerstown, Md, a corporation of Maryland Filed Jan. 27, 1960, Ser. No. 4,908 7 Claims. (Cl. 51-463) This invention relates to vibratory finishing, more particularly the type of vibratory finishing suitable for treatment of work pieces of metal or the like for the purpose of deburring, descaling, cleaning, polishing, burnishing, rounding corners and edges, etc.

The use of vibration for the above purpose has been known for more than ten years as shown by German Patent 691,672, published June 3, 1940, and U.S. Patent 2,422,786, granted June 24, 1947. However, machines built for these purposes have been relatively complicated and cumbersome as well as somewhat awkward to use.

Among the objects of the present invention is the provision of novel equipment and techniques for the above type of vibratory finishing that simplifies and reduces the cost of such treatment.

The above as well as additional objects of the present invention will be more clearly understood from the following description of several of its exemplifications, reference being made to the accompanying drawings wherein:

FIG. 1 is a vertical sectional view taken along the line of 1-1 of FIG. 2 of one form of vibratory finishing apparatus in accordance with the present invention.

FIG. 2 is a front elevation of the apparatus of FIG. 1 with parts broken away to better show some of the details.

FIG. 3 is an enlarged sectional view of one of the support elements of the construction of FIGS. 1 and 2.

FIG. 4 is a sectional view of a drive element in the construction of FIGS. 1 and 2, and

FIG. 5 is a front elevation with a portion broken away of a modified apparatus representative of the present invention.

According to the present invention the above vibratory finishing apparatus has a container for the work articles and vibrating structure connected to vibrate the container, the container being supported by air cushions that provide lateral stiffness of from about 1000 to 5000 pounds per inch, as well as vertical resiliency. These air cushions can be so arranged that they are effectively below the container, preferably with four such cushions arranged in symmetrical spaced relationship, although fewer can be used if desired. It is helpful, however, to have at each supported location an air cushion effectively below the container and another above the container inasmuch as this provides better control over the operation of the apparatus.

Each air cushion can be in the very simple form of a pair of substantially rigid open cups with their open sides facing each other and held apart by a resilient hollow air filled tube having open ends secured in the respective cups. It is also advantageous to have the air cushions connected to a source of air under variable pressure so that the pressure in the air cushions can be altered to thereby vary the resiliency that the cushions provide. All the lower air cushions can, for example, be connected to one source of air, and all of the upper sets of air cushions to another source of air so that the support of each location can be changed through an extremity wide range of resiliency and stiffness.

Another desirable arrangement is to have the lower air cushions on one side of the container connected to a source of air under variable pressure so that by changing the pressure the container support on that side can have its height increased, and/ or decreased, to thereby tilt the 3,053,207 Pa ts 399. 3. 1??? container. Although at each support the air cushions can be provided in pairs, one above and one below the container, the upper one can be omitted. Furthermore, the container tilting can be effected by using variable height cushions on opposite sides of the container, those of one side being increased in height and those on the opposite side being decreased in height. The support for the container conveniently carries the vibrating drive structure and can have a base provided with an additional set of cushions to base the support on the floor or the like. Such additional air cushions can also be arranged to help tilt the container. This help is particularly useful where the container is to be tilted through a relatively large angle, inasmuch as conveniently sized air cushions generally do not provide more than a few inches of height variation.

The above container tilt arrangements are particularly. suitable for use with apparatus designed for subjecting a continuous stream of work articles to vibratory finishing.

Inasmuch as different work articles are usually best treated with different dwell times in the container and the tilt of the container can then be varied to adjust the inclination of the path the work articles take the rough the container, these articles can be caused to traverse the container treatment zone at ahnost any desired speed.

Referring now to the drawings, FIGS. 1 and 2 show a vibratory treatment apparatus having a generally troughshaped container 10 held on a table 12 as by means of bolts 14. Feet 16 secured as by welding to the underside of the container provide convenient flat surfaces at their lower portions for engagement against the table 12. The table is vibrated by means of a shaft 18 having an eccentric weight 20 journalled between two bearings 22 rigidly attached wto'the table as by means of the webs 24 welded to the underside of the table. Skirts 26 depending from I the side edge of the table and also fastened to the webs as well as the table by welding, help to greatly increase the rigidity of the connection to the vibrating drive. The eccentric weight 20 can be replaceably attached as by illustrated bolts 28, so that different weights can be used for modifying the magnitude and frequency of vibration.

The air cushion support is shown as provided by brackets 30 secured against the outer surfaces of the skirts 26 and carrying horizontally extending pads 32 that are received between horizontal flanges 34 and 36 of a supporting framework 38 that encircles the table. Each pad 32 is joined to the flange 36 below it by an air cushion 42, and is also similarly joined by an air cushion 40 to the flange above it.

The framework 3 8 which can merely be a generally rectangular combination of channels 44 and 46 carrying a pair of opposed reinforced sheets 48 to which flanges 34 and 36 are welded, is in turn pivotally held by stub shafts 50 projected from opposite ends of the framework. Journals 52 carried by piers 54 receive the stub shafts and permit the entire framework, including the table and container, to pivot as for the purpose of unloading work articles from the container. The piers 54 can be directly secured to a floor such as a rigid concrete slab, and can also be tied together by a brace 56, shown in the form of a tube. Either or both of the piers can also be used as an anchorage for a tilting mechanism which in the illustrated embodiment is a pneumatic cylinder 58 pivoted directly at its lower end to a bracket 60 held by the piers, and having a movable piston rod 62 connected to a stub shaft 50 by a bell crank 64 which can be secured to a collar 66 keyed to the shaft.

Driving of shaft 18 to cause vibration of the container can be effected as by means of an electric motor carried by the table, the framework, or in any other convenient manner. One highly effective arrangement which reduces the total mass of the vibratory members is to mount such a motor on the framework. In FIG. 2 such a motor is shown at 68 carried by a box 70 depending from the framework alongside the table 12. A drive connection such as a variable ratio pulley combination 72 connects the motor with a jackshaft 74 journalled in bearings 76 and 78 held on a mounting bracket 80 also fitted on the box 70. The jackshaft is in turn coupled to the vibrating shaft 18 by means of a flexible drive coupling 82 shown as having an annularly positioned flexible trough-shaped member 84 clamped between drive discs 86, 88, as more clearly illustrated in FIG. 4.

The air cushions can be of relatively simple construction as indicated in FIG. 3, having an upper cup 90 and a lower cup 92, both of rigid material such as metal, with a flexible open end tube 94 of a material such as rubber or rubber impregnated fabric, connecting them together, the respective ends of tube 94 being secured in the individual cups. To this end the lips of the cups can be turned in, and the ends of the tube molded with an outward flare that mates with the turned-in lips. These tube ends can also be provided with a beading of metal or the like to more securely hold them in place. The central portions of tubes 94 can also be molded with at least a small enlargement so as to assure proper positioning when the cushions are deflated. One of the cups, such as that shown at 92 in FIG. 3, can be equipped with a fitting 96 providing a connection to the interior of the cushion and receiving an air line such as conduit 98.

In the construction of FIGS. 1 and 2 separate conduits are connected, as indicated at 9,8 and 100, to the respective lower and upper sets of air cushions, and also to separate sources of air under pressure. A single main air supply can, for example, be mounted on the piers as indicated at 102, and can be connected by separate adjustable pressure reducing valves to the lines 98, 100. The same air supply can also be used to operate tilting cylinder 58.

The tilting of the container can be arranged to take place in either direction around the framework pivots 50. In fact, dual tilting can also be provided so that the container can be tilted in one direction as for dumping the work, and in the opposite direction for other purposes such as rinsing the work or the container. The container is shown as provided with an internal liner 104 of a resilient material such as natural or synthetic rubber which can be vulcanized in place.

The electric motor 68 is illustrated in FIG. 2 as of the pancake type so as to enable more compact positioning of the various parts within the framework 38, and also reduce the size of this framework. The motor can be protected against wetting as by splash from the container, box 70 being used to so protect the pulley drive. Adjustment for pulley tension is conveniently arranged by having the motor support slidably mounted on the wall of box 70. The motor can, for example, be located on one side of the framework axis, and can be mounted for a slidable adjustment in a horizontal direction.

J ackshaft 71 can also be adjustably positioned vertically so as to stay within the operating tolerances of the coupling 82 insofar as any offset of the jackshaft from the vibration shaft 18 is concerned. A jackscrew 106 threadedly engaged with respect to box 70 and butting against bracket 80 will provide different jackshaft adjustments. In most cases, however, such adjustment is not needed because the air cushioning can be arranged to compensate for changes in weight of container contents, and thereby keep vibrating shaft 18 at a height Well within the limits of the drive coupling. In fact, the air cushions can be made to exactly compensate for changes in container loading, although it may be preferred to control the air cushion characteristics for best vibration treatment rather than primarily for weight adjustment.

The apparatus of FIGS. 1 and 2 is used by loading it with the work pieces as well as any other materials that help in the vibratory treatment. These other materials are generally the same as those used in the well-known barrel finishing of work pieces where the Work is tumbled in a revolving barrel rather than vibrated. Such additional materials include abrasive objects made of ceramic or metal and of such shape that they clean, polish, smooth or round off the work articles, as desired. In addition, liquids are generally used to help suspend particles that are removed from the work pieces, and keep them from becoming re-imbedded in the work pieces. The liquids are generally aqueous and contain dispersing agents with or without soaps. Emulsions or solutions can be used, and where descaling is to be carried out, the liquid can also contain ingredients such as acids that dissolve the scale. The selection of the particular combination of abrasive media and liquids is well known to those skilled in the art and forms no part of the present invention. Reference is made to Metals Handbook, 1948 edition, published by The American Society for Metals, Cleveland 3, Ohio, pages 301 to 305, as well as US. Patents 2,318,581 and 2,464,- 486, for additional details in this respect.

The container can be filled very close to the top, generally within three inches or so, and the vibration immediately started. The vibration causes the individual solids in the container to be rubber against each other and in addition also causes the entire contents of the container to circulate in more or less circular motion around a center parallel to the vibrating shaft 18. For rough finishing operations, as well as those in which it is desired to markedly round off corners or edges, the air pressures in the respective air cushions can be adjusted so as to produce a large amplitude that is about inch or more, measured at the air cushions themselves. These amplitudes are readily obtained although it is much easier to obtain the higher amplitude when the vibration frequency is brought close to the natural vibration frequency of the apparatus.

Frequency control can be effected by changing the speed of the vibrating shaft 18, as by varying the drive ratio between the pulleys of the pulley drive 72. The pulleys can for instance have tapered belt-engaging surfaces with the respective surfaces movable with respect to the mating surface and mechanically controllable to give the pulleys variable pitch. By controlling the pitch of one pulley and having the halves of the second pulley spring-loaded, the second pulley will automatically undergo pitch changes that compensate for changes in belt tension caused by control changes in the first pulley, and the combined changes will give a new drive ratio. Both pulleys can also be directly controlled if desired.

The vibration frequency can also be changed by using variable frequency sources of electrical power to operate the driving motor or by using a D.C. driving motor with a separate motor generator set to supply variable voltage D.C. power to operate it.

The location of the air cushions below the vibrating container enables larger amplitudes to be more easily obtained as compared with resilient supports at higher levels. Also the use of a table to hold the vibrating container simplifies the removal and replacement of the container, as for example when its lining is to be replaced.

For fine polishing the amplitude can be reduced to the order of inch. Proper frequency adjustment should also be made. For either the coarse or the fine finishing operations the lateral stiffness of the container support should be such that it takes between and 500 pounds to move the container so that its anchorage on an air cushion is shifted of an inch in a horizontal direction perpendicular to the axis of the vibrating shaft. With air cushions having an air chamber six inches in diameter and four inches high, an air pressure of about 25 to 60 pounds per square inch gives good results when used either with the upper set of cushions or the lower set of cushions, and whether or not the upper set is used.

It is also very helpful to provide the lateral stiffness with only one set of the cushions such as the lower set,

and then to use a different pressure in the other set of cushions so as to make some adjustment on the vibration amplitude. Such changes in air cushion characteristics help to provide a vibrating frequency close to the natural vibrating frequency of the loaded container, table and all parts rigidly connected to them, so as to thereby enable more efficient vibration with the available power input.

It is a feature of the present invention that the air cushions provide a much simpler and less massive combination, thereby reducing the total weight of the vibrating assembly as well as that of the support needed to carry it. Compared with a set of supporting springs, as shown for example in US. Patents 2,117,965 and 2,171,- 115, as well as the combination springs shown in the vibrators illustrated on the second page of Schwingmuhle Vibratom catalogue by Siebtechnik GMBH, Mulheim, Ruhr, Germany, distributed in 1952, and copies available from Deutsches Museum Bibliothek, Abteilung Firmenschriften, Munich, Germany, the simplicity and weight reduction of the apparatus of the present invention will be readily apparent. The spring suspension shown in the above catalogue includes not only a complete set of coil springs, but in addition an auxiliary set of leaf springs, and this not only makes a bulky combination but has the disadvantage inherent in the tendency for such leaf springs to fail.

Another feature of the present invention is that less power is needed to operate it as compared with the spring suspended constructions. Inasmuch as each mechanical element develops its own natural vibrating frequencies, unless the natural frequencies of the prior art springs are all identical with the frequency at which the vibration is carried out, each such vibrating element will dissipate appreciable energy. With the air cushion construction, on the other hand, there is essentially only one natural vibrating frequency because of the insignificant masses of the air cushions themselves. Furthermore, by a very simple control of the air pressure in these cushions, the natural vibrating frequency of the apparatus can be effectively varied and thus made to coincide with the frequency of the vibrating drive.

FIG. 5 illustrates a further embodiment of the present invention as applied to machines for subjecting a stream of work articles to vibratory treatment on a continuous basis. Here there is provided a work container 210 of generally elongated shape and suspended on air cushions 242, 243 which in turn rest on fixed piers 254, 255. The piers or the air cushions, or both, may be of different heights so as to incline the container 210 with one of its longitudinal ends 209 higher than the other, 211. Vibration is supplied by an electric motor 268 having a shaft 218 projecting in opposite directions and held in bearings 222 secured to the container by means of transverse plates 224 depending from the bottom of the container and reinforced with side plates 226. Eccentric weights 2-20 fastened to the ends of the shaft 218 are oriented so that they have identical eccentricity.

For continuous operation there is provided a loading device such as the chute 213 which delivers the work articles to the high end of the container. At the same time an unloading device is provided at the low end of the container and in the construction of FIG. 5 is shown in the form of a lip 215 under the outer edge of which is positioned a pair of screens 227 .and 229. Screen 227 is directly below lip 215 and is inclined in a direction that feeds to a removal conveyor 231 objects such as work articles which drop on the screen and are too large to fall through between the screens openings. Screen 229 is directly below screen 227 and is inclined laterally toward a recycling conveyor 233 where it guides objects such as abrasive vibration media, which drop through screen 227 and are too large to fall through the openings of screen 229. Under screen 229 can be placed a receiver 235 for fine particles such as fragments of vibration media, scale and burrs removed from the work articles, etc., as they fall through the openings of screen 229.

Recycling conveyor 233 receives the vibration media and returns them to the feed end of the container 210. It is shown as mounted on a set of three rollers 237, 239, 241. Rollers 237 and 239 are at the ends of the recycling conveyor and are tilted with respect to each other, whereas roller 241 is a guide roller near the upper end of the conveyor positioned parallel to roller 237. Rollers 237 and 241 are in horizontal position whereas roller 239 has its end near the container tilted downwardly so as to cause the upper flight of the conveyor to incline after it passes guide roller 241. Alongside this tilted portion of the conveyor the container 210 has a lip 261 that projects out under the adjacent edge of the tilted conveyor portion.

The recycling conveyor 233 collects the vibration media and raises it up to the level of the guide roller 241 after which its tilted portion causes the raised media to fall into the container. To assure that the media falling onto the conveyor at its lower end does not fall off, a fixed three-sided retainer box 263 can be provided so as to rest lightly against the portion of the upper conveyor flight underneath screen 229. Also to assure that the recycling media all return to the container, a fixed deflecting bar 265 can be rested lightly against the tilted portion of the conveyor.

In operation the construction of FIG. 5 can first have its container supplied with a liquid to be used in the desired vibration treatment and can also be loaded with the abrasive media. The work articles can be fed to it, the vibration started, and the angle of container tilt adjusted so that the work articles take the desired time in traversing the container and then appearing on the unloading screen 227. Once set in this operation, it can be so maintained indefinitely so long .as the work-article feed is continued. For prolonged operations, the liquid in the container may have to be replenished and this can be done either on a batch basis or on a continuous basis. Siphons, not shown, are conveniently used to remove the old liquid while fresh liquid is added gradually so as to effect the change-over. If desired, the fresh liquid can be added at the feed end, and overflow of liquid at the discharge end can then merely be discarded. The abrasive media can also be treated if desired, as by washing, during their recycling travel on conveyor 233. When the continuous treatment draws to a close and the feed of work articles is terminated, the vibration treatment is continued with the abrasive media recycled until all the work articles are unloaded by entrainment with the media. The abrasive media can then be unloaded, if desired, as by shoveling it out of the container, or the container can be made to tilt so as to dump its contents or to increase the longitudinal inclination to such a degree that continued vibration will completely or substantially empty it. Alternatively, the container may have a wall or panel at the lower end 211 made removable so that upon removal its contents will be more readily discharged.

Other modifications of the invention can be made, as for example to have screens 227, 229 arranged for vibration so as to provide a more rapid separation as well as better discharge, particularly when the screens are not tilted very much. Other types of abrasive media recycle can be arranged, such as the use of curved conveyors, or the like. The self-contained vibrating drive of the construction of FIG. 5 can also be used for batch operations as in an apparatus of the type shown in FIGS. 1 and 2, and conversely the separately mounted vibrating drive can be used in the continuous work treatment construction of FIG. 5.

The cushions used in the construction of FIGS. 1 and 2, when supplied in pairs above and below the container table, need not have the individual cushions of each pair directly opposed. These cushions can be offset if desired, and this offsetting is helpful in simplifying the mounting of the cushions. The additional air cushions used for supporting the base of the apparatus can be identical with the cushions illustrated in the figures, or they can be different in size and/or shape. The cushions used to support the table, or the container where a table is omitted, can also be varied in size and shape and where pairs of cushions are used the individual cushions of each pair need not be identical.

It is preferred that the cushions be protected from mechanical damage as by mounting them internally of the outer walls of the machine. In the case of air cushions for the base, protection is conveniently afforded by surrounding the individual cushions with a pair of loosely fitting tubes, the inner one secured to the ground contact or floor plate, and the outer one secured to the machine base. Each tube should have its unsecured end spaced from the opposed portion of the base mounting so as to permit a small amount of motion between the base and the machine mounting plate. Also the outer tube can have its upper or secured end completely covered so as to be waterproof and thereby act as an umbrella to protect the cushion. The amount of movement permitted by the tubes is very desirably arranged so that the tubes reach the limit of their collapsed travel and firmly engage their opposing members to thereby support the entire apparatus, before the air cushion iscompletely deflated. This is helpful particularly for shipping and erection purposes, and minimizes the possibility of damaging the air cushion. A further improvement is to supply a resilient bumper on the unsecured end of one of the tubes, preferably the inner tube, so as to reduce the shock that might accompany rapid deflation. The same bumper can also extend laterally to further absorb lateral deflection shocks. The unsecured end of the outer tube can be provided with a travel clearance somewhat greater than that of the inner tube so as to keep the outer tube from engaging its collapsed stop and thereby avoid any pinching action.

Although the construction of FIGURE is shown as not including a table or container support such as is shown at 12 in FIGURE 1, such a container holder can be provided, especially Where the container 210 is to be dismounted at regular intervals for replacing its liners or the like. Such liners are generally vulcanized or similarly secured in place and this type of securing is preferably carried out with equipment specially designed for this purpose and not generally available in the field. However liners can also be cemented in place in the field if desired.

The work containers in accordance with the present invention can be used in uncovered condition as illus-- trated, or they can be provided with covers as for example to maintain a desired atmosphere in the work container or for the purpose of assisting with screening operations or rinsing operations. One very desirable form of cover has a tapered mounting clip along one edge for engaging an edge of the container, which edge may be flanged as also illustrated in FIGURES l and 2. The opposite edge of the cover can be provided with one or more toggle clamps or the like which can be secured to the cover and clamped against the edge of the container. The taper of the cover mounting clip is arranged so as to cam the cover against the open face of the container when the cover is slipped into position, and before the clamp is set.

Perforated covers when used for rinsing can be fitted over the container at the end of the vibration treatment or when the treatment goes from one stage to another and the liquid contents are to be replaced or removed. Perforated covers can be made of sheet material or of screening, held in a suitable framework and with the openings or screening of any desired mesh. A fairly coarse mesh is suitable for general use and will keep work articles as well as most media particles from spilling out of the container when it is tilted for example. Finer meshes are sometimes needed for use with extremely small work pieces or small particles of vibratory media, and such fine screens can either be provided with their own frames or can be inserted under a coarser screen. The tapered clip arrangement permits the lifting of the main screen and the insertion of an auxiliary screen underneath, whenever this is desirable.

Where the vibrating drive uses a motor separately mounted on the support that carries the container and its table, the pancake type of motor construction is an unusually effective one, particularly when the pancake motor has a mounting flange along one face of the pancake. The motor can then be mounted in place by bolts or the like extended through bolt receiving apertures in the motor flange as well as in the wall to which the motor is mounted. The bolt receiving apertures in the wall can be elongated so as to be in the shape of slots and thereby allow adjustment of the motor position, or the slots can be in the motor flange for the same purpose. A feature of this construction is that the motor can be very simply adjusted by tilting the apparatus and permitting the motor to move under the influence of its own weight. Thus by simply loosening the motor fastening bolts when the apparatus is tilted toward the unloading position, the motor can be held in place by its drive belt, so that the proper belt tension is obtained, after which the mounting bolts are again clamped in place to secure the drive. To change adjustments the apparatus with the motor bolts loosened is tilted toward operating position so as to permit the motor to slide down its mounting slots and loosen its belt. The belt can then be replaced if desired. Either of the belt pulleys can also be adjusted at that time, should the pulley drive 'be of the type that has only one of its pulleys adjustable.

Another feature of the pancake motor combination is that such a motor is mounted in a location extremely close to its center of mass, and the stator windings of such a motor do not have free hanging end turns which can, due to vibratory action, become abraded damaging the motor.

The above features of the pancake motor when considered along with the shortening of the overall length which is thereby obtained makes this an unusually desirable arrangement.

The moving of work articles along the vibrating container as for continuous flow treatment, is affected by the relationship of the vibrating shaft 18 with the longitudinal axis of the container. If the shaft is not exactly parallel to that axis, the vibration causes the container contents to move toward the container portions having the greater amplitude of vibration. As little as 1 degree of angularity or skew will give a perceptible longitudinal or flow motion, and sometimes normal variations in manufacturing of the structural components have to be compensated -for to avoid such motion. A skew of 2 or 3 degrees is very helpful in bringing about rapid flow motion, and this can be used to help discharge the container contents from one of its longitudinal ends. This action should be avoided with batch type operation where it has the effect of segregating the Work pieces as well as of the media, in longitudinally localized strata.

The flow through the container can be arranged to take place without tilting the container, by utilizing the above skew action. Furthermore, or in place of skew action, the work flow will result from the mere loading of the container. As loading takes place, the contents of the container tend to overflow inasmuch as they are in a fluent condition, and the provision of a low spot at a desired location of the container rim, will establish overflow there. The faster the loading, the faster the overflow thus caused. The skew action can be used to assist or retard the effect of the loading.

Another feature of the present invention is that the air cushion supports lend themselves admirably to vibrations at frequencies different from the natural frequency of the vibrating assembly. In fact the vibratory finishing action is generally speeded up when the vibrating frequency is brought to about 1500 cycles per minute and most machines will have natural frequencies of the order of 900 or fewer cycles per minute. This appears to be a characteristic of the type of vibration needed, which is gyratory in nature.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Apparatus for subjecting work articles to vibratory finishing treatment, said apparatus having a container for the work articles and vibrating structure connected to vibrate the container, the container being supported by air cushions that provide lateral stiifness of about 1000 to 5000 pounds for a one inch deflection, and also provide vertical resiliency, the air cushions being conncctable to a source of air under Variable pressure for varying the resiliency of the support they provide.

2. The combination of claim 1 in which the air cushions are held on a base so that the container is supported by means of the air cushions on said base, and the base has an additional set of air cushions by which the base is supported when it is placed on a floor.

3. Apparatus for subjecting work articles to vibratory finishing treatment, said apparatus having a container for the work articles and vibrating structure connected to vibrate the container, the container being supported at a plurality of spaced locations, and in each location there is an air cushion effectively below the container and an air cushion effectively above the container, both of the last mentioned air cushions being held by the container support and engaging the container.

4. The combination of claim 3 in which at least some of the air cushions are connected to variable pressure air supplying structure for varying the resiliency of the support provided by these cushions.

5. The combination of claim 3 in which all the lower air cushions are connected to one source of air under pressure, and all the upper air cushions are connected to another source of air under pressure for separately contolling the resiliency of the different sets of cushions.

6. Apparatus for subjecting Work articles to vibratory finishing treatment, said apparatus having a resiliently supported container for the work articles and vibrating structure connected to vibrate the container, the vibrating structure including a drive mechanism held by a support and having a resilient connection to the container to efliciently transmit the vibration drive regardless of the type of motion the vibrating container goes through and regardless of the efiect of the weight of the container load on the height of the container, said connection having a rubber toroidal ring clamped into engagement 'With opposed drive discs.

7. The combination of claim 6 in which the drive mechanism includes a pancake-type motor mounted on the drive connection side of the container.

References Cited in the file of this patent UNITED STATES PATENTS 2,115,072 Hunt et al Apr. 26, 1938 2,353,492 OConnor 7 July 11, 1944 2,423,019 Haines June 2'4, 1947 2,636,7119 OConnor Apr. 28, 1953 2,819,046 Jandris et al Jan. 7, 1958 2,941,816 Benson June 21, 1960 2,993,585 Musschoot July 25, 1961 UNITED STATES PATENT OFFICE CERTIFICATE, OF CORRECTION Patent No. 3 O68 207 November 15 1962 Ralph W., Moore It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 66,, for "extremity" read extremely column 2, line 23 for "the rough" read through column 3, line 57 for "horizontal" read vertical column 4, line 241 for "rubber" read rubbed -o Signed and sealed this 23rd day of April 1963,

(SEAL) *Attest:

ERNEST w. SWIDER DAVID LADD Attesting Officer Commissioner of Patents 

